21773697 has 16 divisors (see below), whose sum is σ = 31752192. Its totient is φ = 13162320.

The previous prime is 21773683. The next prime is 21773701. The reversal of 21773697 is 79637712.

It is not a de Polignac number, because 21773697 - 2⁸ = 21773441 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21773657) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 19488 + ... + 20574.

It is an arithmetic number, because the mean of its divisors is an integer number (1984512).

Almost surely, 2^21773697 is an apocalyptic number.

It is an amenable number.

21773697 is a deficient number, since it is larger than the sum of its proper divisors (9978495).

21773697 is a wasteful number, since it uses less digits than its factorization.

21773697 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1708.

The product of its digits is 111132, while the sum is 42.

The square root of 21773697 is about 4666.2294199921. The cubic root of 21773697 is about 279.2398471944.

The spelling of 21773697 in words is "twenty-one million, seven hundred seventy-three thousand, six hundred ninety-seven".